Clonal lifespan of Paramecium tetraurelia: effect of selection on its extension and use of fissions for its determination

1987 ◽  
Vol 88 (1) ◽  
pp. 129-138
Author(s):  
Y. Takagi ◽  
T. Nobuoka ◽  
M. Doi
Keyword(s):  
Marked Effect ◽  
Marker Genes ◽  
Paramecium Tetraurelia ◽  
Random Events ◽  
The Mean ◽  
Human Diploid Cells ◽  
Diploid Cells ◽  
Poor Nutrition ◽  
Selection Of

Paramecia cells, like human diploid cells cultured in vitro, provide a useful model system for understanding the mechanism that limits division potential. The reported maxima of the clonal lifespan of Paramecium tetraurelia fall into two ranges: from 220 to 258 fissions and from 310 to 325 fissions. We found that neither the selection of vigorous lines nor the cryptic occurrence of autogamy offers a plausible explanation for the much longer lifespans in the latter range. We found the sporadic occurrence of very long clonal lifespans, such as 330 fissions, without selection and autogamy. Selection, which was evaluated by using different methods to maintain lines, had little effect on the extension of the maximal clonal lifespan, whereas it did have a marked effect on the extension of the mean clonal lifespan. Autogamy, which was checked with two closely linked marker genes, was frequent, but only during the period when lines were terminating. Statistical analysis on the mean clonal lifespans of two groups of subclones cultured at 25 and 20 degrees C or with rich and poor nutrition showed that the clonal lifespan that was fission-related under favourable conditions tended to dissociate from fissions under less favourable conditions. We discuss mechanisms that determine the clonal lifespan, programmed events contributing to the maximum clonal lifespan and random events contributing to the mean clonal lifespan.

scholarly journals The effect of oxygen and vitamin E on the lifespan of human diploid cells in vitro.

1977 ◽  
Vol 74 (1) ◽  
pp. 58-67 ◽  
Author(s):  
A K Balin ◽  
D B Goodman ◽  
H Rasmussen ◽  
V J Cristofalo
Keyword(s):  
Oxygen Toxicity ◽  
Alpha Tocopherol ◽  
Ambient Oxygen ◽  
Oxygen Tensions ◽  
Effect Of Oxygen ◽  
Population Doublings ◽  
Human Diploid Cells ◽  
Diploid Cells ◽  
Phase Out

Human diploid cells (WI-38) were serially subcultivated at partial pressures of oxygen (Po2) ranging from 5.6 mm Hg to 608 mm Hg. At a Po2 of 5.6 mm Hg, the number of doublings to phase out was less than that of control cells at a Po2 of 137 mm Hg. Cultures grown at Po2's of 24, 49, or 137 mm Hg grew at the same rate and phased out after a similar number of population doublings. Population lifespan was markedly shortened by chronic exposure to elevated Po2's, a phenomenon that was, in part, reversible. d-1-alpha-Tocopherol (10 microgram/ml or 100 microgram/ml) homogenized into the medium at each weekly subcultivation did not extend the lifespan of cells at reduced, ambient, or elevated oxygen tensions. These results indicate that neither oxygen toxicity nor free radical reactions play a significant role in limiting the lifespan of WI-38 cells grown in vitro under ambient oxygen tensions (Po2 137 mm Hg).

scholarly journals A plant regeneration platform to apply new breeding techniques for improving disease resistance in grapevine rootstocks and cultivars

2019 ◽  
Vol 12 ◽  
pp. 01019 ◽  
Author(s):  
S. Sabbadini ◽  
L. Capriotti ◽  
C. Limera ◽  
O. Navacchi ◽  
G. Tempesta ◽  
...  
Keyword(s):  
Marker Gene ◽  
Marker Genes ◽  
Wine Grape ◽  
Thompson Seedless ◽  
Multiple Virus ◽  
Almost All ◽  
New Breeding Techniques ◽  
Breeding Techniques ◽  
Selection Of

Worldwide grapevine cultivation is based on the use of elite cultivars, in many cases strictly linked to local important wine brands. Most of Vitis viniferacultivars have high susceptibility to fungal and viral diseases therefore, new breeding techniques (e.g. Cisgenesis, RNAi and gene editing) offer the possibility to introduce new clones of the main cultivars with increased diseases resistance, in order to reduce environmental impact and improve quality in the intensive wine grape industry. This study is finalized to develop efficient in vitro regeneration and transformation protocols to extend the application of these technologies in wine grape cultivars and rootstocks. With this aim, in vitro regeneration protocols based on the production of meristematic bulks (Mezzetti et al., 2002) were optimized for different grapevine cultivars (Glera, Vermentino, Sangiovese, Thompson Seedless) and rootstocks (1103 Paulsen, and 110 Richter). The meristematic bulks were then used as explants for Agrobacteriummediated genetic transformation protocols, by comparing the use of NPTII and e-GFP as marker genes. Results confirmed the efficiency of meristematic bulks as the regenerating tissue to produce new modified plants in almost all the above genotypes. The highest regeneration efficiency in some genotypes allowed the selection of stable modified lines/calli with only the use of e-GFP marker gene. This protocol can be applied in the use of MYB marker gene for the production of cisgenic lines. Genotypes having the highest regeneration and transformation efficiency were also used for transformation experiments using a hairpin gene construct designed to silence the RNA-dependent RNA polymerase (RpRd) of the GFLV and GLRaV3, which would induce multiple virus resistances, and the Dicer-like protein 1 (Bc-DCL1) and Bc-DCL2 to control B. cinerea infection.

scholarly journals Selection of male goat embryos in vitro by using swim-up of epididymal spermatozoa

2018 ◽  
Vol 42 (1) ◽  
pp. 79-86
Author(s):  
Ihsan H. S. Al-Timimi
Keyword(s):  
Polymerase Chain Reaction ◽  
In Vitro Fertilization ◽  
In Vitro Maturation ◽  
Chain Reaction ◽  
Vitro Fertilization ◽  
The Mean ◽  
Polymerase Chain ◽  
Epididymal Spermatozoa ◽  
Selection Of

     The main objectives of this study is the separation of X from Y bearing epididymal spermatozoa of local buck by swim-up, and the use of this spermatozoa for in vitro fertilization to determine the percentage of produced male and female embryos. The sex of produced embryo was identified by polymerase chain reaction. Testis of the local buck were obtained from Al-Shu'alah abattoir and the epididymal spermatozoa were harvested from the cauda by and submitted to in vitro maturation prior to separation of X from Y bearing spermatozoa and prior to their use for in vitro fertilization. For the separation of epididymal spermatozoa, swim-up technique was used with centrifugation at 200×g or 300×g. The centrifugation at 200×g showed that 41.84±1.39 % of spermatozoa were detected in the supernatant while the precipitate contained 50.69±0.71 and the mean of the sperm lost was 7.65±0.93. After centrifugation, spermatozoa in the supernatant were used for in vitro fertilization of matured oocytes. The sex of in vitro produced goat embryos was determined by polymerase chain reaction using specific primers to detect of SRY gene. The percentage of total goat embryos obtained after in vitro fertilization by sperms selected using swim-up at centrifugation force of 200×g recorded 79.66 % male embryos while female embryos recorded only 20.33 %. At the end, the results showed the ability of selection male embryos in caprine by application of swim-up technique on epididymal spermatozoa with centrifugation at 200×g.

316 DEVELOPMENTAL COMPETENCE OF OOCYTES SELECTED BY THE BRILLIANT CRESYL BLUE STAINING IN PREPUBERTAL AND ADULT CATTLE

2007 ◽  
Vol 19 (1) ◽  
pp. 273 ◽  
Author(s):  
M. Tagawa ◽  
S. Matoba ◽  
M. Okada ◽  
K. Metoki ◽  
K. Imai
Keyword(s):  
Farm Animals ◽  
Blue Staining ◽  
Blastocyst Formation ◽  
Adult Cattle ◽  
Brilliant Cresyl Blue ◽  
Cresyl Blue ◽  
Significant Difference ◽  
The Mean ◽  
Selection Of

Transvaginal ultrasound guided ovum pickup (OPU) can be carried out repeatedly not only in adult cows but also in prepubertal calves. Moreover, recently the brilliant cresyl blue (BCB) staining has been used successfully to select oocytes homologous stained with BCB as an indirect measure of oocyte growth for in vitro fertilization (IVF) in several farm animals. The aim of this study was to evaluate the effectiveness of BCB staining on the selection of developmentally competent oocytes, collected from cows and calves by OPU, before in vitro maturation by assessing the embryonic development to the blastocyst stage after IVM/IVF. OPU was performed once weekly for a period of 7 weeks on Japanese Black prepubertal calves (9 months old, n = 4) and adult cows (n = 4) without gonadotropin stimulation. Calf and cow oocytes with homogeneous cytoplasm were exposed to 26 �M BCB for 90 min and classified according to their cytoplasmic coloration: blue coloration (BCB+) or colorless (BCB-). Classified oocytes were then matured for 20 h in TCM-199 supplemented with 5% calf serum (CS). Matured oocytes were inseminated with Percoll-separated spermatozoa (3 � 106 mL) for 6 h in BO solution supplemented with 5 mM hypotaurine and 2 U mL-1 heparin. Presumptive zygotes were cultured in CR1aa supplemented with 5% CS for 8 days. Data were analyzed by Student's t-test. The mean (± SEM) percentage of oocytes classified as BCB+ in calves was significantly lower than that in cows (34.4 ± 2.9% and 69.2 ± 2.1%, respectively; P < 0.01). In cows, BCB+ oocytes showed significantly higher cleavage and blastocyst formation percentages (72.5% and 42.4%, respectively) than those of BCB− oocytes (47.0% and 13.0%, respectively). In contrast, in calves there were no significant differences in cleavage and blastocyst formation percentages between BCB+ oocytes (56.9% and 25.3%, respectively) and BCB− oocytes (65.4% and 22.4%, respectively). The mean (± SEM) numbers of usable oocytes and blastocysts obtained per calf (19.0 ± 1.5 and 4.5 ± 0.6, respectively) were similar to those obtained per cow (16.4 ± 1.1 and 5.2 ± 0.6, respectively). No significant difference was observed in the numbers between calves and cows. These results indicate that the selection of developmentally competent oocytes before IVM/IVF, using the BCB staining, was effective for cow oocytes but not for calf oocytes, and that blastocysts could be produced by OPU-IVF of oocytes from 9-month-old prepubertal calves at an efficiency equivalent to that achieved from adult cows.

Cell-associated pentosidine as a marker of aging in human diploid cells in vitro and in vivo

1998 ◽  
Vol 105 (3) ◽  
pp. 221-240 ◽  
Author(s):  
David R Sell ◽  
Michael Primc ◽  
Irwin A Schafer ◽  
Maureen Kovach ◽  
Miriam A Weiss ◽  
...  
Keyword(s):  
Human Diploid Cells ◽  
Diploid Cells
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